The millimeter-wave (mmWave) frequency spectrum offers substantial promise for use in accommodating the ever-growing demand for wireless cellular data service. The mmWave spectrum contains a large amount of available bandwidth, and the physical properties of mmWave signals may support the application of robust beamforming and/or spatial multiplexing techniques and enable significant data rate improvements relative to the data rates achieved via lower frequency bands.
In order to enable mmWave-capable mobile devices in a given physical region to realize such benefits, one or more mmWave-capable small cells (MCSCs) may be deployed in that region. In each MCSC, an mmWave-capable control node may transmit synchronization (“sync”) signals to enable mmWave-capable mobile devices to discover that MCSC. The transmissions of such sync signals may be highly directional, and may be swept through various sectors of the MCSC in sequence. As mmWave signals tend to be more susceptible to attenuation than are signals of lower frequency bands, MCSCs may tend to be fairly small. As such, MCSC deployments may often be relatively dense, especially in high-traffic areas.
The directional nature of MCSC sync signals can present challenges with respect to MCSC discovery, and dense MCSC deployments can add to those challenges. According to conventional techniques, to maintain an acceptably low degree of latency with respect to MCSC detection, the mmWave-capable mobile device may be forced to scan the mmWave band on a virtually continuous basis, resulting in rapid power consumption.